In recent years, mobile terminal devices such as notebook computers, cellular phones and personal digital assistants (PDAs) are increasingly widespread. As secondary batteries used as a power source for these mobile terminal devices, lithium ion secondary batteries are frequently used. Mobile terminal devices are rapidly made smaller, thinner, and lighter with higher performance. As a result, mobile terminal devices come to be utilized in a variety of occasions. Accordingly, secondary batteries are, similarly to mobile terminal devices, required to be made smaller, thinner and lighter with higher performance.
Aiming at enhancement of the performance of secondary batteries, improvement of electrodes, electrolytic solutions, and other battery members is being studied. Among these, the electrode is usually manufactured by obtaining a slurry composition by mixing an electrode active material with a liquid composition in which a polymer serving as a binder is dispersed or dissolved in a solvent, then applying this slurry composition onto a current collector, and drying the applied slurry composition. As to the electrode manufactured by such a method, there has been made an attempt to realize higher performance of secondary batteries by improvement of binders (see Patent Literatures 1 to 5).